"People imply that mental-health patients are capable of these acts," says Tietze. "They don't deserve to be associated with a fascist mass killer."

Many of Breivik's statements fit with the views of the extreme right. "We have to name his ideas for what they are," says Tietze.

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People with mental illness don't deserve to be associated with fascist mass killer Anders Breivik (Image: KeystoneUSA-ZUMA/Rex Features )